A solid oxide is used for an electrolyte membrane included in solid oxide fuel cells (SOFC). Thinning the electrolyte membrane is desired for the enhanced ion permeability of the electrolyte membrane. Such thickness reduction of the electrolyte membrane, however, has difficulty in independently forming the electrolyte membrane. One known technique accordingly forms electrodes and an electrolyte membrane on a support plate made of a porous metal material.
The support plate of the metal material and the electrolyte membrane of the solid oxide have different rates of shrinkage in the course of sintering the electrolyte membrane. The different rates of sintering-induced shrinkage may cause the sintered electrolyte membrane to be detached from the support plate or may be cracked or broken on the support plate. As is known in the art, the solid oxide is shrunk in the course of sintering by 50% in volume and by 15% through 35% in length, width, and height or in respective dimensions in X, Y, and Z directions. The metal support plate, on the other hand, substantially has no shrinkage in the course of sintering.
This problem is not characteristic of the electrolyte membrane but similarly arises on the electrode formed between the metal support plate and the electrolyte membrane.